A majority of the components of a hand held cutting torch have become relatively standardized in their function, structure and appearance. However, continuing development of the structure for mixing the oxygen and the fuel for the preheat flame of the torch has occurred in an effort to overcome long existent problems with hand held cutting torches. These problems include the susceptibility of the torch to potentially dangerous flashbacks or popping caused by the burning of the fuel-oxygen mixture within the torch itself. These flashbacks create high pressure shock waves within the torch which can rupture the wall of the torch or cause a chain reaction of flashbacks sending burning fuel and oxygen upstream in one or both of the fuel and oxygen supply lines.
The flashback problem is worsened when using so called low pressure fuels such as MAPP gas in a torch which is designed for higher pressure gases such as acetylene.
Other problems with prior art torches include incomplete or inconsistent mixing of the oxygen of the oxygen and fuel resulting in rough and unstable preheat flames.
Prior attempts to overcome these problems have included the use of relatively complex mixing structures employing intricate passageways and/or heat absorbing and shock wave dissipating spirals placed within the passageways.
None of the prior art techniques has been perfectly successful in preventing flashbacks, and while many have resulted in satisfactory mixing of the oxygen and fuel gas, all of the prior art structures have involved relatively intricate and expensive machining which has unnecessarily increased the cost of producing the cutting torches.